﻿#region license

// Copyright (c) 2021, andreakarasho
// All rights reserved.
// 
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
// 1. Redistributions of source code must retain the above copyright
//    notice, this list of conditions and the following disclaimer.
// 2. Redistributions in binary form must reproduce the above copyright
//    notice, this list of conditions and the following disclaimer in the
//    documentation and/or other materials provided with the distribution.
// 3. All advertising materials mentioning features or use of this software
//    must display the following acknowledgement:
//    This product includes software developed by andreakarasho - https://github.com/andreakarasho
// 4. Neither the name of the copyright holder nor the
//    names of its contributors may be used to endorse or promote products
//    derived from this software without specific prior written permission.
// 
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS ''AS IS'' AND ANY
// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
// WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE FOR ANY
// DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
// (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
// LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
// ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

#endregion

using System;
using System.Collections.Generic;

namespace ClassicUO.Utility
{
    internal class QueuedPool<T> where T : class, new()
    {
        private readonly Action<T> _on_pickup;
        private readonly Stack<T> _pool;


        public QueuedPool(int size, Action<T> onpickup = null)
        {
            MaxSize = size;
            _pool = new Stack<T>(size);
            _on_pickup = onpickup;

            for (int i = 0; i < size; i++)
            {
                _pool.Push(new T());
            }
        }


        public int MaxSize { get; }

        public int Remains => MaxSize - _pool.Count;

        public T GetOne()
        {
            T result;

            if (_pool.Count != 0)
            {
                result = _pool.Pop();
                _on_pickup?.Invoke(result);
            }
            else
            {
                result = new T();
            }

            return result;
        }

        public void ReturnOne(T obj)
        {
            if (obj != null)
            {
                _pool.Push(obj);
            }
        }

        public void Clear()
        {
            _pool.Clear();
        }
    }
}